Effect of trabecular bone contour on ultimate strength of lumbar vertebra after bilateral ovariectomy in rats

S. Ikeda et al., Effect of trabecular bone contour on ultimate strength of lumbar vertebra after bilateral ovariectomy in rats, BONE, 28(6), 2001, pp. 625-633
Citations number
Categorie Soggetti
Endocrynology, Metabolism & Nutrition","da verificare
Journal title
ISSN journal
8756-3282 → ACNP
Year of publication
625 - 633
SICI code
To test the hypothesis that the effect of trabecular microarchitecture on b one strength varies with the duration of estrogen loss, we evaluated the re lationship between three-dimensional (3D) parameters for trabecular microar chitecture and bone minerals with the compressive load of the lumbar verteb ra in rats. Female Sprague-Dawley rats (n = 190) were divided into 19 group s, Ten rats were killed at day 0. Half of the remaining rats underwent bila teral ovariectomy tow), and the others were subjected to sham surgery. Ten rats from each group were killed at 3, 7, 11, 14, 28, 42, 56, 70, and 84 da ys postsurgery, Urinary deoxypyridinoline and serum osteocalcin increased s ignificantly in the ovx group from days 28 and 11, respectively, compared w ith the sham group. Bone mineral content (BMC) and bone mineral density (BM D) of the fifth lumbar body diminished from days 42 and 84, respectively, c ompared with the sham group. In ovx rats, trabecular bone volume (BV/TV), m easured using 3D images of microcomputed tomography, diminished from day 28 compared with both baseline control and sham, The trabecular bone pattern factor (TBPf) and structure model index (SMI) increased from day 28 in the ovx group compared with both baseline control and sham, Ultimate compressio n loads diminished at day 28 compared with baseline control and decreased p rogressively thereafter. Neither of these parameters changed in the sham gr oup during the same period. Within 4 weeks post-ovx, TBPf, SMI, and BV/TV c orrelated with load (p < 0.01). BMC and BMD correlated with load from 6 wee ks post-ovx (p < 0.01). Stepwise regression analysis showed that TBPf was t he most significant determinant of load within 4 weeks post-ovx (coefficien t of determination [R-2] = 0.669; p < 0.01). SMI correlated with TBPf (R-2 = 0.968; P < 0.01). Moreover, R-2 for ultimate load indicated higher values of 0.975 with TBPf and SMI, However, BMC was the most significant determin ant of load from 6 weeks post-ovx (R-2 = 0.511; p < 0.01), as it was in the sham group. These data suggest that changes in trabecular bone contour wit h increased bone turnover are critical for reducing lumbar bone strength du ring the early post-ovx period in rats. (C) 2001 by Elsevier Science Inc. A ll rights reserved.